4103 — Racial differences in treatment and survival of Stage I NSCLC: a comparison of Veterans Affairs (VA) and SEER-Medicare populations

Lead/Presenter: Ivey Redding,  COIN - Durham
All Authors: Williams CD (Durham VA Healthcare System), Alpert N (Department of Population Health Science and Policy, Institute for Translational Epidemiology, Icahn School of Medicine at Mount Sinai, New York), Redding TI (Durham VA Healthcare System) Bullard AJ (Durham VA Healthcare System) Taioli E (Department of Population Health Science and Policy, Institute for Translational Epidemiology, Icahn School of Medicine at Mount Sinai, New York)

Objectives:
The objective of this study is to compare racial differences in demographic, clinical, treatment, and survival characteristics among veteran and non-veteran patients with stage I NSCLC.

Methods:
Patients with stage I NSCLC diagnosed 2001-2009 were identified in the Surveillance, Epidemiology, and End Results (SEER)-Medicare database and Veterans Affairs (VA) cancer registry. Analyses were restricted to Black and White males aged ?65 years. Logistic regression models estimated odds ratios (OR) and 95% confidence intervals (95% CI) and Cox proportional hazards models were used to assess 5-year survival.

Results:
Among patients in VA (N = 7895) and SEER (N = 8744), the proportion of Black patients was 13% and 7%, respectively. In VA, 50% of both Black and White patients were diagnosed at ages 65-74 years (p = 0.60); in SEER, Black patients were younger than Whites (60% vs 50%, p < 0.0001). The predominant histology was squamous cell in Blacks (47%) and adenocarcinoma in Whites (42%) in SEER; 40% of both Blacks and Whites in VA had squamous cell histology. Ater adjusting for covariates, Blacks were less likely than Whites to get any treatment (ORadj: 0.66, 95% CI 0.57-0.77 in VA; ORadj: 0.56, 95% CI 0.47-0.68 in SEER), and to receive surgery alone when treated (ORadj: 0.73, 95% CI 0.62-0.86 in VA; ORadj: 0.57, 95% CI 0.47-0.70 in SEER). Among treated patients, there was no significant difference in overall survival for Blacks and Whites, after adjusting for type of treatment (HRadj: 0.99, 95% CI 0.91-1.09 in VA; HRadj: 1.00 95% CI 0.89-1.13 in SEER).

Implications:
Among older stage I NSCLC patients, the proportion of Blacks in VA was nearly twice that in SEER, and Blacks and Whites were more similar in VA than in SEER. Despite population differences, similar racial differences in receipt of treatment were noted in both veteran and non-veteran cohorts. No significant racial difference in survival was observed in either cohort when type of treatment is accounted for.

Impacts:
This work supports the hypothesis that equal treatment is associated with equal outcomes among Blacks and Whites with stage I NSCLC and emphasizes the need to understand multi-level predictors of lung cancer treatment disparities.